AbstractExperiments on animals have shown an effectiveness of cord blood stem cells (SCs) in restoration of myocardial contractility. But there is not enough information about the use of this SCs type at heart lesion in people. Therefore, the aim of this study was to analyze the effect of cord blood SCs transplantation on impaired myocardial contractility of patients with chronic heart failure.Materials and methods. According to the data echocardiography we analyzed the changes of intracardiac hemodynamics in patients with decreased myocardial contractility, who underwent intravenous transplantation of cord blood stem cells in case of ineffective traditional conservative therapy schemes of heart failure (HF).Results. Left ventricular ejection fraction before cord blood stem cells transplantation was 22.0 ± 5.0 %, 1 month after SC transplantation – 22.3 ± 6.5%, and in 3 months – 28.5 ± 7.8 % (p < 0.05). The average stroke index increased from 21.3 ± 3.5 ml/m2 before transplantation up to 29.0 ± 8.5 ml/m2 3 months after transplantation SC (p < 0.05). Statistically significant changes of diastolic function parameters (index e’, E/A, E/e’) and venous stasis have not been established. Before transplantation local cell contractility index (LCI) of basal and middle segments was 2.43 points; 1 month after transplantation LCI decreased to 2.38, and after 3 months – up to 2.18 points (p <0.05).Conclusion. In a short term (1-3 months) after transplantation of cord blood cells there was demonstrated a partial restoration of parameters that characterize left ventricular systolic function, and a significant improvement of impaired heart rate mechanics. No negative effects, complications and side effects have been recorded in short periods of observation after transplantation of cord blood cells.